JP2002186670A - Angiographic catheter - Google Patents

Abstract

(57) [Problem] To provide a catheter for angiography in which the lateral movement and opening deformation of a loop portion at a distal end are reduced, and the stimulation applied to a living tissue is reduced. A pigtail-shaped loop portion (12) is formed directly or via an angle portion (13) at the tip of a main tube (11), and the main tube (11) or the angle portion (1) is formed.
3 is provided with a plurality of side holes 2 in the angiographic catheter,
Formed in substantially parallel to the straight portion 12a within a range of ± 20 ° with respect to a direction parallel to the length L ₁ of the straight portion 12a to 4-10 times the lumen diameter φ tube, and said plurality of The most downstream side hole 2a among the side holes is
2 from the rear end to the main tube side
Distance fold equivalent disposed L ₂ within.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catheter for angiography, and more particularly, to a pigtail type catheter in which the lateral movement and opening of a loop portion at a distal end of a pigtail type catheter are reduced to reduce irritation to a living tissue. The present invention relates to a catheter for angiography.

[0002]

2. Description of the Related Art In general, a pigtail catheter is used as a catheter for imaging the left ventricle of the heart. This pigtail-type catheter forms a loop with its tip deformed like a pig's tail, inserts the loop from the femoral artery, and enters the left ventricle while manipulating the guidewire inserted into the catheter. Let it do. Then, a contrast agent is injected from the proximal end of the catheter, and is injected into the left ventricle through an opening or the like at the tip of the loop portion, and the state at that time is photographed by X-rays.

FIG. 4 shows a distal end portion of a conventional pigtail type catheter which enters the left ventricle as described above. The catheter 31 made of a flexible tube has a pigtail-shaped loop portion 42 formed at the tip of the main tube 41, and a plurality of side holes 32 provided at an upstream portion of the loop portion 42. When a contrast agent is injected from a proximal end (not shown) of the catheter 31, the contrast agent is injected from a plurality of side holes 32 on the distal end side and an opening 34 on the distal end of the loop portion 42.

However, the amount and speed of ejection of the contrast agent ejected from the plurality of side holes 32 and the opening 34 at the tip are largest from the opening 34 at the tip.
Therefore, due to the reaction force of the jet power injected from the opening 34 at the tip of the loop portion 42, the loop portion 42 moves laterally (oscillates) as shown by a chain line and is deformed into a state where the tip is opened.
The lateral movement and the opening deformation of the loop portion 42 may stimulate the living tissue, causing complications or hindering appropriate diagnosis and treatment.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the above-mentioned problems of the conventional pigtail type catheter, reduce the lateral movement and open deformation of the loop portion at the tip, and reduce the stimulus to the living tissue. An object of the present invention is to provide an angiography catheter.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a pigtail-shaped loop portion formed directly or through an angle portion at the tip of a flexible main tube, and the main tube or the angle portion. In a vascular contrast catheter having a plurality of side holes, the distal end of the loop portion is set to ± 2 with respect to a direction parallel to the main tube.
It is formed into a substantially parallel straight portion within the range of 0 °, and the length L ₁ of the straight portion is set to 4 mm of the tube lumen diameter φ.
To 10 times, and that the most downstream side hole of the plurality of side holes was placed rear to within a distance L ₂ of the 5-fold equivalent of the tube lumen diameter φ to the main tube side from the said loop portion It is a feature.

As described above, a substantially straight portion is formed at the end of the loop portion, and the straight portion is substantially parallel to the direction parallel to the main tube (± 20).
While the ° in) sequences, since the length L ₁ of the straight portion was 4-10 fold lumen diameter φ of the tube, the axial direction substantially the reaction force of the main tube when the injected contrast medium from the straight portion The direction can be the same, and as a result, the lateral movement and the opening deformation of the loop portion at the tip can be reduced.

Further, a side hole located at the most downstream side among a plurality of side holes provided in the main tube or the angle portion is connected to the main tube side from the rear end of the loop portion by a tube bore diameter of 5 mm.
Since placed within the fold considerable distance L _2, the contrast medium ejection amount ejected from the most downstream side hole, it increases the reasons described below, the ejection amount and ejection speed from the opening of the loop tip as a result Since it is reduced and the injection reaction force in the axial direction of the main tube is also reduced, the stimulus applied to the living tissue can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings.

FIG. 1 exemplifies a pigtail type distal end portion of an angiography catheter according to an embodiment of the present invention.

The angiography catheter 1 is made of a flexible tube. A pigtail-type loop 12 is formed at the tip of a substantially straight main tube 11 and an opening 4 is provided at the tip. A plurality of side holes 2 are helically arranged along the longitudinal direction from the rear end of the loop portion 12 to the upstream side.

A guide wire 3 is inserted through the lumen of the angiography catheter 1 and extends from a base end (not shown) to a loop portion 12. When the distal end portion of the guide wire 2 is advanced and retracted at the proximal end portion of the catheter 1 so as to enter the lumen of the loop portion 12, the curved loop portion 12 changes to a straight state and is retracted. The original curved state is restored.

The material of the tube constituting the angiographic catheter 1 is not particularly limited as long as it has flexibility. For example, polyethylene, polypropylene,
Polyolefins such as ethylene-vinyl acetate copolymer,
Polyamide resins such as nylon 11, nylon 12, and nylon 6, polyurethane, ABS resin, fluorine resin, and polyimide can be used. As a material of the guide wire, stainless steel or the like is preferable.

In the angiographic catheter of the present invention, the distal end side of the loop portion 12 is formed as a substantially straight portion 12a. And, the straight portion 12a has a length L ₁ is formed in a range of 4-10 times the lumen diameter in the tube phi, ± 20 ° with respect to a direction parallel to the main tube 11
, And have a substantially parallel relationship.

As described above, the straight portion 12a is formed at the distal end side of the loop portion 12 and is arranged substantially parallel to the direction parallel to the main tube 11, so that the contrast agent ejected from the opening 4 at the distal end can be formed. The jet reaction force can be stabilized so as to be substantially the same as the axial direction of the main shaft 11. As a result, the loop portion 1 when the contrast agent is jetted
2 can be substantially eliminated, and the stimulus applied to the living tissue can be reduced.

[0016] Moreover, the straight portion 12a, by you have a length L ₁ in the 4 to 10 times the range of lumen diameter φ tube, ejection when the ejection of the contrast agent from the distal end opening 4 as described above The direction of the reaction force can be stabilized, and the lateral movement (lateral run-out) and the opening deformation of the loop portion 12 can be further reduced. The length L ₁ of the straight portion 12a is less than 4 times the lumen diameter φ tube, since the reaction force component in the direction perpendicular to the axial direction of the main tube 11 is increased, stabilization of the direction of the jet reaction force Becomes difficult. On the other hand, if the length is more than 10 times, it is advantageous for stabilizing the direction, but there is a problem that the diameter of the loop portion 12 becomes unnecessarily large.

Of the side holes 2 provided in the main tube 11, the side hole 2a located at the most downstream position
That is, for the side hole 2a closest to the loop portion 12, a distance L ₂ equivalent to five times the tube bore diameter φ from the inner end (upstream end portion) of the loop portion 12 to the main tube 11 side.
Are provided in the range. Note that the inner end of the loop portion 12 is a boundary point at which the loop portion 12 moves to the main tube 11, and a point at which the curvature of the loop portion 12 first becomes 0 (the radius of curvature is infinite). .

[0018] By thus the position of the most downstream side hole 2a is set to the range of the distance L _2, the contrast agent is set to the maximum ejection amount and ejection speed of injection from the most downstream side hole 2a The amount and speed of jetting from the opening 4 at the distal end can be reduced by the increased amount, so that the jet reaction force applied in the axial direction of the main tube 11 can be reduced. Therefore, the stimulus given to the living tissue can be further reduced.

Such effects are obtained from the results of the following studies by the present inventors. That is, when a plurality of side holes are arranged in the main shaft, it is considered from the fluid mechanics that the side holes at the tip end gradually increase in ejection amount and ejection speed. However, the present inventors have conducted CAE analysis (C
According to the results of omputer Aided Engineering Analysis) and experiments, the change in the injection amount and ejection speed is not linear. placing in the range of 5 times the distance L _2, was obtained a finding that the ejection amount and ejection speed of injection from the most downstream side holes can be increased up to three times or more.

Therefore, by specifying the position of the most downstream side hole within the range of the distance L ₂ corresponding to five times the tube bore diameter φ from the inner end of the loop portion based on the above knowledge, This makes it possible to suppress the ejection reaction force when the contrast agent is ejected from the opening 4 at the tip end to be minimized.

A plurality of side holes 2 provided in the main tube 11
The method for arranging is not particularly limited.
As shown in (A), it is good to arrange spirally around the main tube 11. By arranging the spirals in this manner, the direction in which the contrast agent is ejected from each side hole 2 is diffused in all directions around the main tube 11. Can be prevented.

In order to further improve the effect of arranging the plurality of side holes 2 in a spiral shape, as shown in FIG. 2B, when the plurality of side holes 2 are viewed in a tube cross section, they are adjacent to each other. The phase angle α with respect to the axis of the tube between the side holes is 30 °
It is preferable to set it in the range of 60 °. In particular, the phase angle α is preferably set to 45 °.

The diameter d of the side hole is preferably in the range of 0.5 to 1 times the tube bore diameter φ, and the pitch P between adjacent side holes is 1 to 3 times the side hole diameter d. A range is preferred.

FIG. 3 illustrates an angiographic catheter according to another embodiment of the present invention.

The angiographic catheter 1 shown in FIG. 3 does not have the loop 12 formed directly at the distal end of the main tube 11 as in the embodiment shown in FIG. This facilitates insertion of the loop portion 12 into the ventricle. The configuration other than the angle portion 13 is substantially the same as the catheter of FIG.

[0026]

Example: Using a polyethylene tube (outer diameter 1.6 mm, inner diameter 1.2 mm), the shape of the pigtail type loop at the tip (Figs. 1 and 4), the total number of side holes, and the most downstream from the rear end of the loop 18 types (Examples 1 to 6 and Comparative Examples 1 to 1) in which the positions (distances) to the side holes were different as shown in Table 1.
Pigtail type angiography catheter 2) was manufactured.

Since the inner diameter φ of the tube is 1.2 mm, the length L ₁ of the straight portion described in the text is L ₁ =
1.2 mm x (4 to 10) = 4.8 to 12 mm,
The distance L ₂ is L ₂ = 1.2 mm × 5 = 6 mm.

With respect to these 18 types of angiographic catheters, the flow rate injected from the tip opening of the loop portion when water was injected at an injection rate of 12 ml / second for 1.5 seconds (total injection amount 18 ml), The lateral deflection and open deformation of the part were examined. Table 1 shows the results.

[0029]

[Table 1] Table 1 shows that the angiographic catheter of the present invention (Examples 1 to 5).
In the case of 6), since the lateral vibration and the opening deformation are not substantially generated and the amount of the jet from the opening at the tip is reduced, it is understood that the jet reaction force against the main tube is also reduced.

[0030]

As described above, according to the present invention, the tip of the loop portion is formed as a substantially straight straight portion, and the straight portion is substantially parallel to the direction parallel to the main tube. (Within ± 20 °) and the length L ₁ is 4 to 10 times the tube bore diameter φ, so that the reaction force when the contrast medium is injected from the straight portion is equal to the axial direction of the main tube. The directions can be substantially the same, and as a result, the lateral movement and the opening deformation of the loop portion at the tip can be reduced.

Further, of the plurality of side holes provided in the main tube or the angle portion, the side hole located at the most downstream side is connected to the main tube side from the rear end of the loop portion by 5 mm in tube bore diameter φ.
Since placed within the fold considerable distance L _2, the contrast medium ejection amount ejected from the most downstream side hole, it increases the reasons described below, the ejection amount and ejection speed from the opening of the loop tip as a result Since it reduces the injection reaction force of the main tube in the axial direction, the stimulation applied to the living tissue can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view illustrating a distal end portion of an angiographic catheter according to an embodiment of the present invention.

FIGS. 2A and 2B show a main tube portion of the angiography catheter shown in FIG. 1, wherein FIG. 2A is a front view and FIG. 2B is a sectional view taken along line XX in FIG.

FIG. 3 is a front view illustrating a distal end portion of a catheter for angiography according to another embodiment of the present invention.

FIG. 4 is an explanatory view showing a conventional pigtail type catheter.

[Explanation of symbols]

 Reference Signs List 1 catheter 2 side hole 2a (located at the most downstream) side hole 3 guide wire 4 opening 11 main tube 12 curved deformation part 12a straight part 13 angle part

Claims (5)

[Claims] An angiography catheter having a pigtail-shaped loop formed directly or via an angle portion at the tip of a flexible main tube, and having a plurality of side holes in the main tube or the angle portion. In the above, the tip of the loop portion is formed as a straight portion substantially parallel to the direction parallel to the main tube within a range of ± 20 °, and the length L ₁ of the straight portion is set to the tube lumen diameter. to 4-10 times phi, and the arrangement of the most downstream side hole of the plurality of side holes, the rear end within a distance L ₂ of the 5-fold equivalent of the tube lumen diameter phi to the main tube side from the said loop portion Angiographic catheter. 2. The angiographic catheter according to claim 1, wherein the side holes are spirally arranged around a tube. 3. The angiographic catheter according to claim 2, wherein the phase angle α between the adjacent side holes with respect to the tube axis is in the range of 30 ° to 60 °. 4. The angiographic catheter according to claim 1, wherein the diameter d of the side hole is 0.5 to 1 times the tube bore diameter φ. 5. The angiographic catheter according to claim 1, wherein an arrangement pitch P of the side holes is set to be 1 to 3 times the side hole diameter d.